I have an asbestos corrugated garage roof, approximately 2.4m by 6.5m. The roof has considerable moss growing on it, and because my house is pebble dashed there are lots of stone pebbles scattered along the roof edging. The roof has started to leak in a few places, mainly where the roof butts up against the main wall of the house. I think this is because of the excessive moss, and the stone pebbles, that’s stopping the water from running off into the gutter ie there are pools of water just sitting on the roof. There are also one or two cracks, but not too many.

I can’t afford to have the roof replaced right now so as a short term measure I thought I would have the roof cleaned ie remove the moss & pebbles. Of course I understand that because of the asbestos gloves and a mask should be worn for health & safety. However I do have two questions . Firstly can a crack on an asbestos corrugated sheet be repaired and how?... Secondly, after the cleanup is there something that can be used to treat the asbestos corrugated sheets ie something I can paint or spray onto the sheets to make it more waterproof/protect it etc?

I contacted a local roofer and he has given me a quote of £590, and for that he said he would... "clean the roof of all moss, seal any cracks with seal tape, and coat whole roof area with industrial sealer with added fibres".

Is this a reasonable quote?... to be honest it's a little bit more than what I was expecting. In fact do I really need to use a Roofer, wouldn't a competent handyman be able to do the work?

Decided to do the job myself, instead of using a contractor. But I don't have any boards that I can use to stand on whilst working on the roof. I thought of using a couple of scaffolding boards, but it's not something Wickes sell???

Can someone please advice what I can use as a crawling board while I'm up on the corrugated roof eg would a plywood sheet/board be good enough and if so what thickness?... of course I'll make sure it's long enough to span at least two of the roof rafters/beams :)